Gary Lauder, a venture capitalist and co-founder of the Aspen Institute's Socrates Society, ran through the numbers as part of a presentation last month as part of the TED Talks series, and the numbers are shocking.
Lauder looked at T-type intersections where a three-way stop sign setup was installed, yet vehicles rarely approach the intersection from one of the sides. He found that for the straight section of the intersection, 3,000 cars each way passed through the intersection, each using an average two ounces, or about five cents, of extra gasoline to accelerate from a complete stop. Added up, that's more than $51,000 per year in gasoline.
Then adding up the time lost stopping at stop signs, he calculated that, given ten seconds of delay per stop, there's 8.3 hours of total delay per day, per stop sign. Multiply that by a $20-per-hour wage and you get nearly $61,000 in lost money, potentially—or in total, about $112,000. That's for one intersection, so it would be fair to say that the costs of stop signs rank in the billions.
Over time, for all the money lost due to many intersections, it could potentially cover the cost of purchasing the adjacent property and installing a roundabout.
But replacing intersections with roundabouts in our very grid-based road system is costly, and it isn't going to happen on a large scale anytime soon.
According to Lauder's proposed system, for an intersection that would currently have stop signs in all directions, a new 'Take Turns' sign, which would combine features of stop and yield signs, would be placed on the busier of the two roads, while the road with the lighter traffic would still have a normal stop sign. This would eliminate the ambiguity for those on the busier road when no other traffic is present but allow more caution in letting them turn in when there's a constant stream of traffic.
"The great frustration of waiting for one's chance to jump in is a major source of accidents," commented Lauder on an information page.